The following description relates to techniques and methods for inserting a bulb into a vehicular lamp.
A conventional bulb insertion structure of a vehicular lamp (Japanese Patent Laid-Open Publication No. 9-219103), as shown in FIGS. 8 and 9, is constituted by a cylindrical socket fixture 2 fixed to a bulb insertion hole 1a of a reflector 1, and a cup-shaped socket 6 which can accommodate therein a rear end portion of a bulb 4 and covers an outer periphery of the socket fixture 2 from the rear. The socket fixture 2 and the bulb 4 are provided with three fixing protrusions 2a and three engaging protrusions 5a that respectively correspond, and the outer periphery of the socket 6 is provided with three J-shaped slots (hereafter referred to as “J-slot”) 7 at positions corresponding to the protrusions 2a and 5a. Furthermore, a spring 8 for energizing the bulb 4 forward is provided in an inner portion of the socket 6 in which the rear end portion of the bulb 4 can be accommodated.
To insert the bulb 4 into the bulb insertion hole 1a, as indicated by an arrow A in FIG. 9, the bulb 4 is inserted in the socket fixture 2 to conform the engaging protrusion 5a with the fixing protrusion 2a. Next, as indicated by an arrow B in FIG. 9, the socket 6 covers the socket fixture 2 such that the J-slot 7 aligns with both protrusions 5a and 2a. Then, when the socket 6 is pushed forward against the energizing force of the spring 8 and rotated clockwise, the fixing protrusion 2a and the engaging protrusion 5a engage with the J-slot 7. As a result, the socket 6 is fixed to the socket fixture 2, creating a state where the bulb 4 is inserted into the bulb insertion hole 1a as shown in FIG. 8.
Furthermore, the J-slot 7 is provided with an engaging recess portion 7a for holding the engaging protrusion 2a when the socket 6 is pulled out, so that the socket 6 can be detachably attached with the bulb 4 in an integrated state.
That is by covering the socket fixture 2 with the socket 6 integrated with the bulb 4 by engaging the engaging protrusion 5a with the J-slot 7 such that the J-slot 7 conforms with the fixing protrusion 2a, in addition to pushing the socket 6 against the energizing force of the spring 8 and rotating the socket 6 clockwise, the fixing protrusion 2a and the engaging protrusion 5a engage with the J-slot 7. Consequently, the bulb 4 is inserted into the bulb 4 insertion hole as shown in FIG. 8.
Furthermore, to pull the bulb 4 out from the bulb insertion hole 1a, the engaging protrusion 5a engages with the engaging recess portion 7a, and (a protrusion-sliding slit 7b of) the J-slot 7 opens when the socket 6 is pushed in against the energizing force of the spring 8. Therefore, by rotating the socket 6, the fixing protrusion 2a slides along the slit 7b, disengaging the fixing protrusion 2a and the J-slot 7, and thus the socket 6 integrated with the bulb 4 can be pulled out from the socket fixture 2.
However, in the conventional structure described above, cases occur in which the socket 6 is fitted in an incomplete form when fitting the socket 6 integrated with the bulb 4 to the socket fixture 2.
As shown in FIG. 10A, the bulb 4 and the socket 6 may be integrated in a manner such that the engaging protrusion 5a on the bulb side abuts the protrusion-sliding slit 7b of the J-slot 7. When the socket 6 integrated with the bulb 4 is fitted to the socket fixture 2, the socket 6 is pressed and rotated as shown in FIG. 10A and by arrows A1 and A2 in FIG. 10B, and the engaging protrusion 5a and the socket 6 integrally rotate with respect to the fixing protrusion 2a as shown in FIG. 10B. The engaging protrusion 5a may not slide with respect to the J-slot 7, and only the fixing protrusion 2a slides as indicated by an imaginary line in FIG. 10B. Then, as shown in FIG. 10C, the fixing protrusion 2a engages with the J-slot 7, however, the engagement between the engaging protrusion 5a on the bulb side and the J-slot 7 is maintained in an incomplete state.